infirmed

Example:He has been weakened by the long illness, and is in need of care.

Definition:made less strong; reduced in strength

Example:Old age has disabled many of the senior citizens, making travel more difficult for them.

Definition:incapable of performing normal functions due to injury, illness, or the effects of aging

Example:He was invalided out of the army due to lingering health problems after the war.

Definition:someone who is physically handicapped or very weak due to prolonged or serious illness